#ifndef _MY_MEMDC_H_
#define _MY_MEMDC_H_

//////////////////////////////////////////////////
// CMyMemDC - memory DC
//
// Author: Keith Rule
// Email:  keithr@europa.com
// Copyright 1996-1999, Keith Rule
//
// You may freely use or modify this code provided this
// Copyright is included in all derived versions.
//
// History - 10/3/97 Fixed scrolling bug.
//                   Added print support. - KR
//
//           11/3/99 Fixed most common complaint. Added
//                   background color fill. - KR
//
//           11/3/99 Added support for mapping modes other than
//                   MM_TEXT as suggested by Lee Sang Hun. - KR
//
// This class implements a memory Device Context which allows
// flicker free drawing.
class CMyMemDC : public CDC 
{
protected:
	CBitmap  m_bitmap;       // Offscreen bitmap
	CBitmap* m_oldBitmap;    // bitmap originally found in CMyMemDC
	CDC*     m_pDC;          // Saves CDC passed in constructor
	CRect    m_rect;         // Rectangle of drawing area.
	BOOL     m_bMemDC;       // TRUE if CDC really is a Memory DC.

	void Construct(CDC* pDC)
	{
		ASSERT(pDC != NULL); 
		// Some initialization
		m_pDC = pDC;
		m_oldBitmap = NULL;
		m_bMemDC = !pDC->IsPrinting();
		if (m_bMemDC) {
			// Create a Memory DC
			CreateCompatibleDC(pDC);
			pDC->LPtoDP(&m_rect);
			m_bitmap.CreateCompatibleBitmap(pDC, m_rect.Width(), m_rect.Height());
			m_oldBitmap = SelectObject(&m_bitmap);

			SetMapMode(pDC->GetMapMode());
			pDC->DPtoLP(&m_rect);
			SetWindowOrg(m_rect.left, m_rect.top);
		} else {
			// Make a copy of the relevent parts of the current DC for printing
			m_bPrinting = pDC->m_bPrinting;
			m_hDC       = pDC->m_hDC;
			m_hAttribDC = pDC->m_hAttribDC;
		}
		// Fill background 
		FillSolidRect(m_rect, pDC->GetBkColor());
	}
	// TRK begin
public:
	CMyMemDC(CDC* pDC) : CDC() { pDC->GetClipBox(&m_rect); Construct(pDC); }
	CMyMemDC(CDC* pDC, const RECT& rect) : CDC() { m_rect = rect           ; Construct(pDC); }
	// TRK end

	virtual ~CMyMemDC()
	{        
		if (m_bMemDC) {
			// Copy the offscreen bitmap onto the screen.
			m_pDC->BitBlt(m_rect.left, m_rect.top, m_rect.Width(), m_rect.Height(),
				this, m_rect.left, m_rect.top, SRCCOPY);            

			//Swap back the original bitmap.
			SelectObject(m_oldBitmap);        
		} else {
			// All we need to do is replace the DC with an illegal value,
			// this keeps us from accidently deleting the handles associated with
			// the CDC that was passed to the constructor.            
			m_hDC = m_hAttribDC = NULL;
		}    
	}

	// Allow usage as a pointer    
	CMyMemDC* operator->() 
	{
		return this;
	}    
	// Allow usage as a pointer    
	operator CMyMemDC*() 
	{
		return this;
	}
};

#endif